1. Brief Description of the Prior Art
It has been previously proposed to pivotally secure a ripper tooth to the back side of a backhoe bucket in a position such that the tooth can penetrate into the soil, particularly when the backhoe is tucked or folded upwardly. The ripper tooth carries a sharp pointed cap on its lower digging end, and this enables it to slash deeply into the ground, or even through very hard material in the soil. By reason of the pivotal mounting of the tooth on the backhoe, it can be pivoted about a horizontal axis to an operative position in which the point extends downwardly and slightly forward at a time when the bucket carrying the tooth at its rear side is tucked upwardly in a stored or inactive position by use of a hydraulic cylinder and in a conventional fashion.
In general, the type of ripper tooth which has been mounted on the back of a backhoe carry an aperture through the tooth which permits it to be pivotally pinned between a pair of ears secured to the rear side of the backhoe bucket at a time when it is desired to keep the digger tooth in a inoperative position relative to the backhoe.
A problem which has been encountered in constructions of the type described which have a ripper tooth attached to the back side of the backhoe bucket is that the opposite end of the pivoted ripper tooth from that which carries the pointed cap bangs against the top side of the backhoe bucket repeatedly as the ripper tooth is used. In some cases, the impact transmits large forces to the top of the backhoe bucket as the ripper tooth engages hard rock during the downward travel of the backhoe bucket to which it is mounted. The hard metal of the ripper tooth at this blunt end location can wear into, and damage, the backhoe bucket.
One type of ripper tooth or tine structure which has been used by securement to the back side of a backhoe bucket has carried the blade shank in a fixed, downwardly extending position. Since this causes the ripper tooth to interfere with the backhoe bucket when the bucket is to be used alone, it is possible to attain full and efficient usage of the bucket only by removing the ripper tooth. In some digging situations, the inconvenience and inefficiency is simply tolerated. It is also more difficult to effectively use this fixed position ripper tooth, even when ripping is the only type of digging to be performed.
2. Brief Description of the Present Invention
The present invention relates to a ripper tooth attachment assembly which is constructed specifically t facilitate its attachment by welding or the like to the convex back side of the backhoe bucket so that a ripper tooth forming a part of the assembly can be used in aid of the excavating action normally realizable from the backhoe bucket. The ripper tooth attachment assembly can be quickly and easily secured to the backhoe bucket, and functions effectively in use to impale and dig into hard soils, and loosen these soils for later effective removal by the backhoe in conventional digging action.
Broadly described, the ripper tooth attachment assembly of the invention includes a mounting base subassembly which is adapted to be attached to the convex rear side or bottom of a backhoe bucket. The mounting base subassembly includes a generally rectangular base plate which carries a pair of spaced attaching plates on one side of the base plate. Each of these spaced attaching plates carries a concave free edge which is configured in its curvature to mate with the convex arcuate rear side of the backhoe bucket. Thus, these attaching plates can be easily welded over their entire length to the back side of the backhoe bucket due to their complementary configuration.
The opposite side of the rectangular base plate carries a pair of spaced, parallel tooth-mounting ears or lobes which project rearwardly, and which define a pair of aligned tooth-mounting apertures or openings which are adapted to receive a pivot pin. In a preferred embodiment of the invention, these openings carry bushings. A pivot pin is extended through the apertures in these ears or lobes, and also through a large bearing sleeve carried in an opening centrally located in an elongated ripper tooth.
The lower end of the thus pivotally mounted ripper tooth carries a detachable point. At its opposite or second end, the elongated ripper tooth carries an impact surface which is positioned to beat or hammer against an impact pad built up at the upper edge of the rear side of the rectangular base plate. The impact pad extends over the entire space between the tooth-mounting ears, and thus functions to distribute the impact forces transmitted thereto during the use of the elongated ripper tooth to the entire base plate, and from the base plate through the mounting base subassembly into the expanse of metal included in the construction of the backhoe bucket.